Attention deficit hyperactivity disorder (ADHD) is also known as attention deficit disorder (ADD). It is estimated that ADHD affects three to five percent of children, adolescents and adults.
Symptoms begin in childhood and include impulsiveness, inattentiveness, distractibility, difficulty staying focused, difficulty with organization, and hyperactivity (over-activity). These symptoms cause a variety of problems at school, work and home, including the ability to learn and get along with others. There are currently three subtypes of ADHD, including predominantly hyperactive-impulsive, predominantly inattentive and combined, but most children have the combined type.